Pre-manufactured wooden trusses greatly facilitate the construction of buildings and other structures. Known trusses are essentially planar structures with spans and heights far exceeding their thickness. One type of truss is the parallel chord type truss. Parallel chord trusses generally include a bottom chord, a top chord vertically spaced and parallel to the bottom chord, and webs extending between the top and bottom chords. The webs may be fabricated from wood and are typically coupled to the top and bottom chords by nailing plates having integrally formed teeth that are configured to be embedded into the surface of the chords and the webs. Alternatively, a parallel chord truss may include metal webs. The metal webs may be U-shaped, V-shaped, W-shaped, or S-shaped and are configured to attach to the vertical surface of the chords, typically with integrally formed teeth protruding from the web. Metal webs are attached to both sides of the truss along the entire length of the truss to provide strength and stability to the truss. A metal web attached to one side of the truss has a corresponding metal web attached to the other side of the truss that is in alignment with the first metal web. A truss with aligned metal webs on opposing sides of the truss provides openings or passage ways through the truss for electrical wires and plumbing pipes.
Parallel chord trusses may be used for floor joists and roof rafters in place of solid lumber 2.times.8, 2.times.10, or 2.times.12 joists. Trusses typically are stronger than solid lumber and permit greater spans and greater spacing between joists. The open web configuration of trusses eliminates the need for drilling passage holes for electrical and plumbing services. However, there is a need for being able to pass more, and/or larger items through the trusses, for example, heating and cooling ducts.
It would be desirable to provide trusses having more and/or larger openings to permit passing more services, such as plumbing pipes and heating and cooling ducts through the trusses while maintaining truss strength.